Memory applications of a thiophene-based conjugated polymer by photoluminescence measurements

Data-storage and memory applications of conjugated polymers and organic semiconductors are generally probed by device current or dielectric properties to determine the storage and switching properties. In this article, we use photoluminescence as an alternate method of probing the states of the devices. We have fabricated such devices based on a polythiophene derivative, and recorded photoluminescence (PL) spectra during and after applying bias. The presence of localized charges on the backbone of the polymer has been found to modulate the PL intensity. Since the relaxation of the space charges is slow, we have shown that PL intensity can be used as a probe for memory applications to read the state of the device. PL as a probe for memory applications of polymeric materials offers an intrinsic advantage that the state can be read without affecting the device properties.